Present avionics communication signal-to-noise squelches are handicapped by the manner in which they measure the noise portion of the ratio. Noise is measured slightly off channel so that the desired on-channel signal power does not interfere with the noise power that must be measured. A traditional receiver contains a hardware-implemented intermediate-frequency (IF) filter that is usually in the form of a high-Q crystal filter or some other high-Q circuit design to give the radio as steep an out-of-band cut off as possible. This IF filter has the undesirable effect of filtering off a portion of the noise that is being measured. The IF filter response can also vary with temperature, thus affecting noise measurement and squelch function. The effect of the IF filter is that the squelch does not always perform predictably, and suffers from the reduced and varying level of the noise being measured.